zaberCommands.py

# Full manual for ASCII Protocol to Zaber Stages: http://www.zaber.com/wiki/Manuals/ASCII_Protocol_Manual
# Python API: http://www.zaber.com/support/docs/api/core-python/0.8.1/

import serial
import time
import sys
import glob
from zaber.serial import AsciiSerial, AsciiDevice, AsciiCommand, AsciiReply, AsciiAxis


def send_rec(msg,ser):
	ser.write(msg)
	line = ser.readline()
	print(line)
	return line


def serial_ports():
	""" Lists serial port names
		:raises EnvironmentError:
			On unsupported or unknown platforms
		:returns:
			A list of the serial ports available on the system
	"""
	if sys.platform.startswith('win'):
		ports = ['COM%s' % (i + 1) for i in range(256)]
	elif sys.platform.startswith('linux') or sys.platform.startswith('cygwin'):
		# this excludes your current terminal "/dev/tty"
		ports = glob.glob('/dev/tty[A-Za-z]*')
	elif sys.platform.startswith('darwin'):
		ports = glob.glob('/dev/tty.*')
	else:
		raise EnvironmentError('Unsupported platform')

	result = []
	for port in ports:
		try:
			s = serial.Serial(port)
			s.close()
			result.append(port)
		except (OSError, serial.SerialException):
			pass
	return result


def check_serial_ports(portType='AsciiSerial'):
	"""
	:return port: Either Zaber AsciiSerial reference or Serial reference to correct COM port
	"""
	# Find serial ports on the system
	COMports = serial_ports()
	#print(len(COMports))

	# Connect to the serial port with the Zaber stage (if more than one on system).
	if len(COMports) == 0:
		print("There are no stages detected on the system")
	elif len(COMports) == 1:
		if portType == 'AsciiSerial':
			port = AsciiSerial(COMports[0])
		elif portType == 'Serial':
			port = serial.Serial(COMports[0],115200,timeout=1)
	else:
		print('Multiple COM ports found, please identify which is connected to Zaber stage')
		c = raw_input('Enter COM port number followed by ENTER: ')
		COMports[0] = ('COM%s' % c)
		if portType == 'AsciiSerial':
			port = AsciiSerial(COMports[0])
		elif portType == 'Serial':
			port = serial.Serial(COMports[0],115200,timeout=1)

	print "Communicating through " + str(COMports[0])

	return port


def initialize_zaber_serial(port, **kwargs):
	"""
	:param port: AsciiSerial COM port reference for stages
	:param kwargs: can specify maximum number of devices to check for (maxDevices=X). Default is 10
	:return devices: list of AsciiDevices corresponding to all Zaber stages
	:return numDevices: number of devices that were found and initialized
	"""
	maxDevices = 10
	for key in kwargs:
		if key == 'maxDevices':
			maxDevices = kwargs[key]

	#print(maxDevices)

	devices = {}
	numDevices = maxDevices
	for i in range(0, maxDevices):
		try:
			devices[i] = AsciiDevice(port, i+1)# Device number i
			devices[i].home()
			print "Stage " + str(i) + " in home position"
		except:
			numDevices = i
			break

	print('The total number of initialized Zaber devices is: ' + str(numDevices))

	return devices, numDevices


def home(devices):
	for device in devices:
		device.home()


def check_command_succeeded(reply):
	"""
	Return true if command succeeded, print reason and return false if command
	rejected

	param reply: AsciiReply

	return: boolean
	"""
	if reply.reply_flag != "OK": # If command not accepted (received "RJ")
		print ("Danger! Command rejected because: {}".format(reply.data))
		return False
	else: # Command was accepted
		return True


if __name__ == '__main__':

	port = check_serial_ports(portType='Serial')

	# 1) USE SERIAL TO TALK TO STAGES DIRECTLY

	# Example set of commands to follow.
	msgs = ['/1 move abs 30000\n','/1 move rel -20000\n','/1 home\n']

	line = send_rec('/2 \n',port)
	if line == '':
		print('no stage at address 2')
	#line = send_rec('/1 \n')
	#print(line)

	# Send them all and see if they are ready.
	for msg in msgs:
		line = send_rec(msg,port)
		# Assume that the stage is doing something.
		busy = 1
		while busy:
			# Send a command that just asks for the status of device 1.
			line = send_rec('/1 \n',port)
			# If it is not doing anything, we can send a new command.
			if 'IDLE' in line:
				# busy = 0
				break
			time.sleep(0.5)

	# Check if there are any unread lines
	line = port.readlines()
	print(line)

	# Close the connection.
	port.close()

	# 2) USE ZABERSERIAL TO TALK TO STAGES
	port = check_serial_ports(portType='AsciiSerial')

	devices,numDevices = initialize_zaber_serial(port,numDevices=10)

	# Move stages, check status
	reply = {}
	for i in range (0,numDevices-1):
		devices[i].move_rel(20000) # move devices 20000 microsteps relative to their current positions
		reply[i] = devices[i].send('get pos')
		if check_command_succeeded(reply[i]):
			print("Device %d is at: " %i + reply[i].data)
		else:
			print("Device move failed.")

	# Close the connection
	port.close()